Slip segment inserts for a downhole tool

Abstract

A downhole tool has a plurality of slip segments with buttons extending therefrom. The buttons will engage the well and may be made from material with no magnetic characteristics, for example, silicon nitride.

What is claimed is: 
     
         1 . A downhole tool for use in a well comprising:
 a mandrel;   a plurality of slip segments disposed about the mandrel and movable from an unset to a set position in the well, the slip segment comprising:
 a slip segment body; and 
 a plurality of buttons extending outwardly from the slip segment body for engaging the well in the set position, the buttons having favorable drillability characteristics, and being able to withstand well pressures of 10,000 psi at a temperature of 325° F. 
   
     
     
         2 . The downhole tool of  claim 1  wherein the insert buttons are silicon nitride. 
     
     
         3 . The downhole tool of  claim 2 , wherein the buttons are SN-235P. 
     
     
         4 . The downhole tool of  claim 1  further comprising a packer disposed about the mandrel. 
     
     
         5 . The downhole tool of  claim 1  wherein the buttons have the drillability characteristics of zirconia ceramic buttons, and the pressure and temperature characteristics of metal composite ceramic buttons. 
     
     
         6 . The downhole tool of  claim 1 , wherein the inserts are comprised of a material with no magnetic characteristics. 
     
     
         7 . The downhole tool of  claim 1 , wherein the inserts are comprised of a non-metallic material. 
     
     
         8 . Apparatus for anchoring a downhole tool in a well comprising:
 a plurality of slip segments disposed about a mandrel of the tool the slip segments comprising:
 a slip segment body having an outer arcuate face, the slip segment body defining a plurality of cavities; and 
 inserts disposed in the cavities, wherein the inserts have drillability characteristics of zirconia ceramic, and are capable of gripping engagement at well temperatures and pressures of up to at least 10,000 psi and 325° F. 
   
     
     
         9 . The apparatus of  claim 8  wherein the inserts are comprised of silicon nitride. 
     
     
         10 . The apparatus of  claim 9 , wherein the inserts are comprised of SN-235P. 
     
     
         11 . The apparatus of  claim 8 , where in the slip segments are movable from an unset to a set position in the well, wherein in the set position the inserts engage a cavity in the well. 
     
     
         12 . The apparatus of  claim 11 , wherein the inserts have the temperature and pressure characteristics of metal composite ceramic inserts. 
     
     
         13 . The apparatus of  claim 8 , wherein the inserts comprise a material having no magnetic properties. 
     
     
         14 . The apparatus of  claim 8 , wherein the inserts comprise non-metallic material. 
     
     
         15 . Apparatus for use in a well comprising:
 a well comprising:
 a mandrel; 
 a plurality of sealing elements disposed about the mandrel movable from an unset to a set position in the well; and 
   slip segments disposed about the mandrel and positioned above and below the sealing elements, the slip segments comprising:
 a slip segment body; and 
 a plurality of buttons extending from the slip segment body, the buttons having favorable drillability characteristics and having no magnetic properties. 
   
     
     
         16 . The downhole tool of  claim 15 , wherein the buttons are comprised of silicon nitride. 
     
     
         17 . The downhole tool of  claim 16 , wherein the buttons are comprised of SN-235P. 
     
     
         18 . The downhole tool of  claim 15 , wherein in the set position, the buttons grippingly engage a casing in the well.